FIRST try using the Ad-Aware program to "quarantine" those "critical objects".
The guidelines on doing that are found by clicking "Help" on the left-hand side
of the "start-up" screen, then double LEFT-clicking on the "Using Ad-Aware SE"
topic, then double LEFT-clicking on the "What is the quarantine?" topic and
following the "instructions" there .
Since "TrojanDownloader.Agent" is a very bad piece of spyware, Ad-Aware
might NOT be able to "handle" it . IF this happens, the use of the "HijackThis"
program will be required, then you should download HijackThis (© Merijn) from: http://www.thespykiller.co.uk/files/HJTsetup.exe
Note: This is a complete installer that installs HijackThis to your computer at C:\Program Files\HijackThis, making an entry in the start menu and also providing a desktop shortcut. If HijackThis is used from a temp folder, it is in danger of being accidentally deleted by clean up tools.
At the download prompt, choose "Save". After the download is complete, navigate to the C:\Program Files\HijackThis folder and double-click it to complete the installation.
Then you would post a "log" from running the program on a Support Forum,
such as on this forum, to have their Experts "review" the Findings and offer